Ike Threat Growing

After quickly ramping up to a Category 4 in a matter of hours on Wednesday, Hurricane Ike has weakened somewhat due to strong wind shear and some dry air. However, don't let that lull you into thinking that Ike has reached its maximum intensity. Unfortunately, it likely hasn't. Recon got into Ike early this afternoon and generally confirmed what satellite estimates have known -- it is a major hurricane with top winds of 115 mph and a minimum pressure of 958 mb. Wind shear still remains on the high side (20 knots), but the large expanse of dry air observed earlier today has since moistened considerably. Therefore, shear is the only factor preventing Ike from strengthening. Furthermore, satellite images do show that outflow along the northern half of Ike is still being restricted due to the strong shear. The eye of Ike has been visible briefly throughout the afternoon but is eroded on the northwest side. The temperature difference between the eye and just outside of the eye wall is somewhat low (5 C), which indicates to me that Ike is not currently a very efficient hurricane. This temperature is normally at least 10 C in mature hurricanes.


The wind shear is forecast to weaken in the next 24-36 hours, and when this occurs, look for Ike to intensify again. One caveat to rapid intensification is the cool waters (80-82 F) just east of the Bahamas that were upwelled by Hanna earlier this week. However, once Ike moves west of the 75 deg W meridian, rapid intensification could commence. Wind shear is forecast to be quite low at that time along with a moist environment and high oceanic heat content. In fact, it should be no surprise if Ike quickly becomes a Category 4 hurricane again by early Monday. Ike should be a very powerful hurricane by Monday and will still remain in a low shear and high oceanic heat environment. However, eye wall dynamics come into play and it's somewhat difficult to forecast the intensity of Ike once it becomes a steady-state mature hurricane. Yes, the environment will be highly supportive of strengthening, but eye wall replacement cycles can create periods of intensity fluctuations. Another dillemma with intensity forecasting past Monday morning involves the potential impacts of land.


This opens up a big can of worms, especially trying to forecast the track of Ike. The easy part of the track deals with the next 48 hours. There is decent model agreement that Ike will move just south of due west during this time frame and should be south of Long Island Sunday afternoon. After this, there is a large amount of spread in the models. The 18Z GFDL, HWRF, UKMET, and 12Z Euro and UKMET all forecast Ike to interact with Cuba and even move over Cuba for nearly 24 hours. Other models like the 18Z GFS and 12Z NOGAPS either show Ike interacting very little with Cuba or moving just north of Cuba. This is a very difficult track forecast because it will also dictate the intensity of Ike. Earlier today, I was leaning with the idea that Hanna would create enough of a weakness in the ridge to keep Ike from moving over Cuba. However, there is very reliable model support for this idea, and I'm now leaning toward the idea of Ike interacting with northern Cuba. I think it will be brief, but it will be enough to at least disrupt the circulation of Ike. Just how much remains to be seen. However, Ike should then pop out into the Straits of Florida on Tuesday and will likely pass just south of Key West if my idea is correct. If Ike does not interact with Cuba, the Florida Keys could be in the direct path of a potential Category 4 or 5 hurricane. I'll stop with the track forecast at this point, but most of the models do agree that Ike enters the Gulf of Mexico next week and could be a major hurricane depending on how much land it encounters.

Needless to say, everyone from Louisiana to Miami needs to pay very close attention to Ike in the coming days. This could be a very powerful hurricane with a major threat to impact the U.S. within the next week. I'll have an update tomorrow morning.